Computers are recovered or replaced conventionally by backing up data and then restoring the backed up data in the case when trouble occurs. For example, data of an operating system (OS) or a business system operated on a computer is backed up for the replace of the computer. The backed up data is then restored on a hard disk of a target computer, for example. This can enable the business system to be resumed on the target computer.
With the conventional methods for replacing computers, however, the business system suspends a restart until restoration of the backed up data is completed. Accordingly to one conventional technology, information on storage areas accessed during activation of the OS is recorded so that the accessed information can be identified. Then, failure recovery is performed using the identified information only.
Patent Document 1 Japanese Laid-open Patent Publication No. 2010-282468
Patent Document 2 Japanese National Publication of International Patent Application No. 2008-547123
However, according to the above technology, not all data used in the business system is restored when the business system is activated. Hence, after the activation, the business system has to wait for the restoration of data, thus prolonging the time the operation does not proceed.
A restoration program according to one aspect of an embodiment of the present invention causes a computer to execute processing in which backup data of an operating system and a business system is restored without running the operating system until a predetermined time point. The predetermined time point is a time point until which the total amount of the data read out along with the start-up of the operating system and a predetermined business system remains equal to or smaller than the total amount of the data that can be restored from the backup data while running the operating system and the business system. The restoration program causes the computer to execute processing that starts up the operating system and the business system, after the backup data is restored until a predetermined time point. The restoration program then causes the computer to execute processing that restores the backup data at the predetermined time point and later, in parallel with the start-up of the operating system and the business system.